Circuit interrupter



July 15, 1941,

F. KESSELRING ETAL CIRCUIT INTERRUPTER Filed Feb. 4, .1959 2 Sheets-611%: l

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Filed Feb. 4, 19:59 2 Sheets-Sheet 2 WITN 43 F f A/ plNVENTORS I r r z a ring au/Du/ lhg d y g dfw emmen Patented July 15, 1941 CIRCUIT INTERRUPTER Fritz Kesselring, Berlin-Frohnau, Paul Dufiing, Berlin-Siemensstadt, and Joseph Behringer, Berlin-Friedrichsfelde, Germany, assignors to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application February 4, 1939, Serial No. 254,614 In Germany February 11, 1938 (C1. BOD-82) Claims.

This invention relates to circuit interrupters and more particularly to operating mechanisms 01 the hydraulic type for high voltage circuit breakers capable of interrupting a high power electrical circuit. In the application of Paul Dufiing, Serial No. 235,608, filed October 18, 1938, and assigned to the assignee of this application, is shown and described a hydraulic operating mechanism for multi-phase breakers, in which the contact structure of each phase has a separate hydraulically actuated operating device. The individual operating devices are simultaneously actuated by a common control pump electrically isolated from the circuit interrupting structure.

The main object of this invention is the provision of improvements in hydraulic operating mechanisms for circuit breakers of the type disclosed in the aforesaid application whereby more efiicient and reliable breaker operation may be obtained.

A more specific object of the invention resides in the provision of a common control device in a hydraulic operating mechanism for actuating the separate control devices of each phase of a multi-phase circuit breaker wherein separate pump pistons, one for each phase, are disposed in parallel spaced relation with respect to each other and mechanically joined to a common actuating member for simultaneous operation.

A. further object of the invention resides in the provision of more effective means for sealing the control pump of a hydraulic breaker operating mechanism against leakage of operating liquid.

Another object of the invention is the provision of improved means for latching a hydraulic operating mechanism for circuit breakers in the closed circuit position.

Still another object of the invention consists in the provision of structure to compensate for any changes in volume of the operating liquid in a hydraulic circuit breaker operating mechanism.

Other objects and advantages relate to the structural arrangement of the several parts constituting the invention and will appear more fully in the following description when read in connection with the accompanying drawings, in which:

Figure 1 is an elevation View of a multi-phase circuit breaker structure partially in section showing the operating mechanism of our invention in schematic form;

Fig. 2 is a sectional View taken along the line II-II of Fig. 1 showing a modified arrangement of the control pump cylinders; and,

Figs. 3, 4 and 5 show diiierent embodiments of an expansion vessel to compensate for changes in volume of the operating liquid in the hydraulic operating system.

In the drawings, the reference numerals l, 9 and H generally designate individual units of a three-phase circuit breaker structure. Each of these units are supported upon a common base l3 and comprise two tubular insulator sections I5 and Il separated by a metallic casing member IS. The insulator ll provides a circuit interrupting chamber 2| which is at least partially filled with a suitable arc extinguishing liquid and contains a circuit interrupting element 23. The circuit interrupting element 23 may be of any conventional form as, for example, of the type shown and described in the application of Paul Dufiing (filed in Germany January 29, 1938), Serial No. 246,410, filed December 17, 1938, and assigned to the assignee of the instant application, and comprises a fixed contact 25 and a movable contact 21. The movable contact 21 extends through a suitable opening in the casing member I9 into the chamber 29 within the supporting insulator I5. To the lower end of the moving contact 21 is secured a piston 3l' guided for reciprocal movement within an operating cylinder 33. The cylinder 33 is open at its upper end and disposed within an insulating tubular member 35 in a manner more specifically set forth in the aforesaid application of Paul Duffing, Serial No. 246,410. For the purpose of this invention, it will sufiice to state that each of the cylinders 33 are provided with an insulating conduit connection 31 for conducting operating liquid thereto. Each of the tubular insulating members 35 also have an insulating conduit connection 39 forming a further passage for operating liquid.

Operating liquid for actuating the pistons 3| to open and closed position is supplied to the individual operating cylinders 33 by a control device generally indicated at 4|, and comprises a case 43 having three individual cylinders 45 disposed in the upper end thereof. The cylinders 45 may be arranged in alignment, as shown in Fig. 1, or disposed in triangular arrangement, as indicated in Fig. 2. Each of the cylinders 45 is connected at its upper end to a corresponding conduit connection 31. Disposed within each of the cylinders 45 is a pump piston 41 having a connecting rod 49 extending downwardly into the casing 43 and joined to a common support member 5i. The three conduits 39 connected to the three tubular members merge in a common conduit 53 which, in turn, is connected to the casing 43. The casing 43, conduits 31, 38 and 53 and tubular members 35 thus form a completely enclosed hydraulic system which is filled with a suitable insulating liquid, for example, oil, chlorinized and fluorized hydrocarbons or the like, for transmitting force from the control pump 4! to the operating pistons 3|.

The pistons 47 are operated by a common operating rod joined to the support member 5| and extending downwardly through a suitable packing gland 51 in the casing 43. The lower end of the operating rod 55 has secured thereto a piston 53 adapted for reciprocating movement in a cylinder 6| secured to the lower end of the easing 43. A compression spring 53 disposed about the operating rod 55 between the casing 43 and the piston 59 biases the pistons 41 to the lowermost position. A suitable source of compressed gas as air (not shown) may be operatively connected to the cylinder 6| through a conduit for actuating the piston 59 against the biasing action of the spring 53, so as to move the three pstons 4i upwardly to simultaneously cause a i flow of liquid in the conduits 3'! in the direction indicated by the arrows. It will be apparent that this flow of liquid will move the operating pistons 3| upwardly in the cylinders 33, thereby moving the contact members 21 to the closed circuit position. The liquid above the pistons 3| in the cylinders 33 will be displaced during the upward movement and caused to flow out of the cylinders 33 into the tubes 35, conduits 39 into the single conduit 53 and into the casing 43.

In order to maintain the piston 59 in the upper-most position against the action of the biasing spring 63, a latching rod 61 is provided extending downwardly from the piston 59 through the end of the cylinder 6|, and has thereon a pivoted latch lever 69 which is adapted to engage a notched portion H of a pivoted latch arm 13. The latch arm 13 is normally maintained in the latching position by an armature 15 of a trip coil magnet Tl. When the trip coil magnet 11 is energized as a result of a predetermined overload condition in the circuit to be interrupted, armature i5 is rocked in a clockwise direction about its pivot releasing the latch arm 13 so that it may rotate in a clockwise direction to release the I latching lever 59 and permit the spring 63 to move the operating rod 55 and its connected pistons 4| downwardly. During the downward movement of the pistons 41 by the action of the springs 63, liquid Within the casing 43 is placed under pressure and moved from the casing into the conduit 53, from whence it divides and moves into each of the conduits 39 into the respective tubular members 35, and then into the upper open ends of the operating cylinders 33 to force the operating pistons 3| downwardly to their open circuit position, The liquid below the pistons 4| will flow through the conduits 3! into the separate cylinders 45.

In order to prevent any loss of liquid from the pump casing 43 through the packing gland 51 into the operating cylinder 6|, a flexible bellows member 19, preferably constructed of metal, is provided encircling the operating rod 55 and joined at its upper end to a suitable flange on the casing 43 and at its lower end to a flange on the piston 59. Thus as the operating rod 55 and the piston 53 are moved up and down, the bellows i9 is alternately collapsed and extended, but at all times protects the seal and prevents leakage of the liquid from the pump chamber. By arranging the three pistons 4'] for simultaneous operation from a single operating rod 55, only one sealing gland need be provided for completely sealing the pump casing.

If an insulating liquid, such as oil, is used in the circuit interrupting chamber 2| for the purpose of bringing about are extinction, the same liquid may be used for driving the actuating means. However, in order to prevent fouling of the driving oil by the arc extinguishing oil, which is contaminated during the circuit opening operation, the passage in the casing member |9 through which the contact 21 moves is also prelerably sealed, thereby preventing the interchange of liquid from the chamber 2| to the interior of the insulating tube 35.

Inasmuch as the liquid within the operating system is subjected to changes in volume, it is expedient to provide an expansion chamber 8| connected by a conduit 83 to the pump casing 43. The expansion chamber 8| is partly filled with liquid so as to provide partially compressed air in the space above the liquid. Thus, as the liquid in the system expands and contracts due to temperature variations, the level of the liquid withi the expansion chamber 8| will rise and fall accordingly, Also, if the liquid within the system is partially diminished as the result of a limited amount of leakage, the liquid within the chamber 8| will provide the deficiency in the system.

In Fig. 3, an elongated metallic expansion chamber 85 is shown completely filled with liquid and connected by conduit 8'! to the pump casing 43. In this instance, the side walls of the expansion chamber 85 are composed of flexible material and easily deformable upon changes of pressure within the pump chamber 43. For example, in the event of expansion of the liquid within the operating system, the side walls of the chamber 85 may be moved outwardly to the dotted position indicated at 89. In the event that contraction takes place of the operating liquid, the side walls may contract to take up the position shown by the dotted lines 9|.

A further arrangement for equalizing the volume variation of the liquid within the operating system is shown in Fig. 4, which does not require the use of an expansion chamber externally of the breaker structure. In accordance with the structure shown in Fig. 4, the space within the upper insulator ll of at least one of the circuit breaker units 1, 9 or H, is divided into two chambers 93 and 95, respectively, by a tubular member 91 disposed concentrically within the insulator H. The chamber 95 in this instance serves as a circuit interrupting chamber for housing the arc extinguishing device 23, whereas the chamber 93 serves as an expansion chamber. The chamber 93 is preferably filled with insulating liquid and connected by conduit 99 to the pump casing 43. The structure in other respects is the same as that previously described.

The arrangement shown in Fig. 5 is, in general, similar to that shown in Fig. 4 with the exception that the conduit connecting the annular chamber 93 with the pump casing 43 has been omitted. In this instance, the flanged casing member l9 between the insulators I5 and l! is provided with a radially extending passage 0| leading outwardly from the tubular member 35. A short vertical passage I03 joins the annular chamber 93 with the passage |0|. The base of the passage |03 is enlarged to accommodate a ball check valve I05. The action of the check valve I is such that during the normal expansion and contraction of the driving liquid in the system, liquid may flow freely to and from the expansion chamber 93. However, during the operation of the hydraulic operating mechanism, pressure conditions are such within the tube that the check valve I05 closes the passage I03 and prevents the loss of pressure from the system.

Although I have shown and described a spe cific circuit breaker structure and a hydraulic operating mechanism therefor, it is to be understood that the same is for the purpose of illustration and that changes and modifications may be made by those skilled in the art Without departing from the spirit and scope of the appended claims.

We claim as our invention:

1. In combination, a polyphase circuit interrupter having a movable contact member for each phase, liquid actuated operating means for each contact member, and liquid actuating means for controlling the movement of said operating means, said liquid actuating means comprising a plurality of cylinders one for each phase having an independent liquid connection with a corre sponding operating means, a piston operable in each of said cylinders and means for rigidly n echanically coupling said pistons to each other for simultaneous operation both during opening and closing of the circuit interrupter,

2. In combination, a polyphase circuit interrupter having a movable contact member for each phase, liquid actuated operating means for each contact member, and liquid actuating means for controlling the movement of said operating means, said liquid actuating means comprising an enclosed chamber, a plurality of cylinders one for each phase having one end in communication with said chamber and the other connected to a corresponding operating means, a piston operable in each of said cylinders and means within said chamber mechanically coupling said pistons to each other for simultaneous operation.

3. In combination, a polyphase circuit interrupter having a movable contact member for each phase, an operating cylinder for each phase, a double acting piston in each operating cylinder for moving said contact members to open and closed positions, a liquid actuating means for controlling the movement of said double acting pistons, said actuating means including a pressure chamber having a separate cylindrical compartment for each phase, a liquid connection from one end of each compartment to one end of a corresponding operating cylinder, a separate piston operative in each of said compartments, means within said pressure chamber mechanically coupling said last named pistons to each other for simultaneous operation, and liquid connections from the other ends of said operating cylinders to said pressure chamber.

4. In combination, a polyphase circuit inter rupter having a movable contact member for each phase, an operating cylinder for each phase, a double acting piston in each operating cylinder for moving said contact members to open and closed positions, liquid circulating means comprising a casing having a cylindrical compartment for each phase, a control piston operable between predetermined positions within each compartment, a common operating member in said casing mechanically joining said control pistons, liquid carrying connections between one end of each operating cylinder and each compartment and between the other end of each operating cylinder and said casing, means for actuating said operating member to move said control pistons to one of said positions for causing said contact members to be moved to the closed position, and means for latching said operating member in said one position.

5. In combination, a polyphase circuit interrupter having a movable contact member for each phase, an operating cylinder for each phase, a double acting piston in each operating cylinder for moving said contact members to open and closed positions, liquid circulating means comprising a casing having a cylindrical compartment for each phase, a control piston operable between predetermined positions within each compartment, a common operating member in said casing mechanically joining said control pis tons, liquid carrying connections between one end of each operating cylinder and each compartment and between the other end of each operating cylinder and said casing, resilient means for actuating said operating member to move said control pistons to one of said predetermined positions for causing said contact members to be moved to the open positions, means opposing said resilient means for actuating said operating member to move said control pistons to antoher predetermined position for causing said contact members to be moved to the closed position, and means for latching said operating member against movement by said resilient means.

6. In combination, a polyphase circuit interrupter having a movable contact member for each phase, an operating cylinder for each phase, a double acting piston in each operating cylinder for moving said contact members to open and closed positions, liquid circulating means com- "rising a casing having a cylindrical compartment for each phase, a control piston operable between predetermined positions Within each compartment, a common operating member in said casing mechanically joining said control pistons, liquid carrying connections between one end of each operating cylinder and each compartment and between the other end of each operating cylinder and said casing, resilient means for actuating said operating member to move said control pistons to one of said predetermined positions for causing said contact memhere to be moved to the open position, an air operated piston for actuating said operating member against the action of said resilient means, to move said control pistons to another predetermined position for causing said contact members to be moved to the closed position, and means for latching said operating member against movement by said resilient means.

'7, In a hydraulic operating mechanism for circuit interrupters having a movable contact member, liquid actuated operating means for said contact member, a liquid moving device for controlling the operation of said operating means, said liquid moving device including a pressure chamber having a cylinder therein, liquid carrying connections from said cylinder and said pressure chamber to said liquid actuated operating means, a piston operative in said cylinder,'an operating cylinder adjacent to said pressure chamber, an operating member for said piston extending through one side of said pressure chamber into said operating cylinder, a fluid actuated piston coupled to said operating memher and operable within said operating cylinder, and a collapsible member surrounding said operating member joined at one end to said fluid actuated piston and at the other to said pressure chamber for sealing said pressure chamber against loss of liquid.

8. In a hydraulic operating mechanism for a multiple circuit interrupter having a movable contact member for each pole, a liquid actuated operating means comprising a liquid actuated piston for each contact member, a liquid moving device for controlling the operation of said operating means, said liquid moving device including a pressure chamber having a pump cylinder therein for each liquid actuated operating means, a liquid carrying connection from one end of each pump cylinder to one side of the corresponding liquid actuated piston, a liquid carrying con nection from the other side of the liquid actuated pistons to said pressure chamber, said pump cylinders communicating at their other ends with said pressure chamber, a pump piston operative in each pump cylinder, means connecting said pump pistons for movement together, a common operating member for said pistons extending through one side of said pressure chamber, and a flexible metal bellows member surrounding said operating member joined at one end to said pressure chamber and at th other end to said operating member for sealing said pressure chamber against loss of liquid.

9. In a hydraulic operating mechanism for circult interrupters having a movable contact member, liquid actuated operating means for said contact member, a liquid moving device for controlling the operation of said operating means, said liquid moving device including a pressure chamber having a cylinder therein, liquid carrying connections from said cylinder and said pressure chamber to said liquid actuated operating means, a piston operative in said cylinder, an operating cylinder adjacent to said pressure chamber, an operating member for said piston extending through one side of said pressure chamber into said operating cylinder, a fluid actuated piston coupled to said operating member and operable Within said operating cylinder, and a metallic bellows surrounding said operating member joined at one end to said pressure chamber and at the other to said fluid actuated piston for sealing said pressure chamber against loss of liquid into said operating cylinder.

10. In combination, a polyphase circuit interrupter having a movable contact member for each phase, an operating cylinder for each phase, a double acting piston in each operating cylinder for moving said contact members to open and closed positions, liquid circulating means comprising a casing having a cylindrical compartment for each phase, a control piston operable between predetermined positions within each compartment, a common operating member in said casing mechanically joining said control pistons, liquid carrying connections between one end of each operating cylinder and each compartment and between the other end of each operating cylinder and said casing, and an expansion chamber having a liquid carrying connection with said casing, said expansion chamber being at least partially filled with liquid under pressure for maintaining said casing and connected parts filled with liquid.

11. In a hydraulic operating mechanism for circuit interrupters having a movable contact member, liquid actuated operating means for said contact member, a liquid moving device for controlling the operation of said operating means, said liquid moving device including a pressure chamber having a cylinder therein, liquid carrying connections from said cylinder and said pressure chamber to said liquid actuated operating means, a piston operative in said cylinder for moving liquid through said connections to said operating means, and an expansion chamber completely filled with liquid connected in liquid exchanging relation with said pressure chamber, the walls of said expansion chamber being deformable in response to changes in pressure within said pressure chamber.

12. In a circuit breaker, a housing having outer and inner tubular members, circuit interrupting means including separable contact means disposed within said inner tubular member, a hydraulic operating mechanism for actuating said contact means to open and closed position, a body of liquid disposed between said outer and inner tubular members, and conduit means for conducting liquid from said body to said hydraulic operating mechanism to compensate for changes in volume of the liquid of said hydraulic mechanism.

13. In a circuit breaker, a housing having outer and inner tubular members, circuit interrupting means including separable contact means disposed within said inner tubular member, a hydraulic operating mechanism for actuating said contact means to open and closed positions, a body of liquid disposed between said outer and inner tubular members, and conduit means for conducting liquid from said body to said hydraulic operating mechanism to compensate for leakage of liquid from said operating mechanism, said conduit means including means for preventing the reverse flow of liquid from said operating mechanism to the space between said tubular members during operation of said operating mechanism.

14. In a circuit breaker, a housing comprising a pair of superimposed tubular insulator columns, a metallic casing member disposed between said insulator columns dividing said housing into upper and lower chambers, a tubular member of insulating material disposed within the upper chamber, a second tubular member disposed in said lower chamber having its upper end sealed to said casing member, circuit interrupting means including a movable contact member disposed within said first tubular member, said contact member extending through said casing member into said second tubular member, hydraulic operating means including said second tubular member for operating said contact member to open and closed positions, a body of liquid disposed between said first tubular memher and the upper insulator column, and a passage through said casing member joining said body of liquid with said second tubular member.

15. In a circuit breaker, a housing comprising a pair of superimposed tubular insulator columns, a metallic casing member disposed between said insulator columns dividing said housing into upper and lower chambers, a tubular member of insulating material disposed within the upper chamber and sealed to said casing member, a second tubular member disposed in said lower chamber having its upper end sealed to said housing member, circuit interrupting means including a movable contact member disposed within said first tubular member, said contact member extending through said casing member into said second tubular member, hydraulic opersaid second tubular member to the space between said first tubular member and the upper insulator column only during operation of said hydraulic operating means.

FRITZ KESSELRING. PAUL DUFFING. JOSEPH BEI-IRINGER. 

